• 한국환경농학회지
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• 제7권1호
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• pp.26-33
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• 1988

제지(製紙)슬러지가 수도생육(水稻生育)에 미치는 영향(影響)을 검토(檢討)하기 위하여 슬러지의 시용량(施用量)을 300, 600, 900 및 1,200kg/10a으로 달리하고 각(各)로 시용수준별(施用水準別)로 C/N율(率)을 30 : 1로 조절(調節)과 무조절구(無調節區)을 두어 pot시험(試驗)을 실시(實施)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 초장(草長), 분벽수(分蘗數) 및 건물중(乾物重)은 수도생육초기(水稻生育初期)에는 슬러지시용량(施用量)이 많을수록 현저히 감소(減少)하였으며 출수기이후(出穗期以後)부터는 슬러지의 C/N율조절구(率調節區)가 3요소구(要素區)에 비하(比)여 증가(增加)하였다. 2. 식물체중(植物體中) 질소(窒素), 린산(燐酸), 칼리 및 규산(珪酸)의 흡수량(吸收量)은 생육초기(生育初期)에 있어서는 슬러지구가(區) 3요소구(要素區)에 비(比)하여 현저히 감소(減少)하였으나 유수형성기이후(幼穗形成期以後)부터는 슬러지구(區)가 증가(增加)하였으며 C/N율조절구(率調節區)는 무조절구(無調節區)에 비해(比) 더욱 증가(增加)하였다. 3. 식물체중(植物體中) 아연(亞鉛), 동(銅) 및 카드뮴의 함량(含量)은 각각(各各) $39{\sim}101$, $0{\sim}0.11$ 및 $0.03{\sim}0.14ppm$ 범위(範圍)였으며 납 및 크롬은 검출(檢出)되지 않았다. 물체중(物體中) 이들 중김속함량(重金屬含量)은 처리간(處理間)에 차이(差異)가 없었다.

• 한국응용과학기술학회지
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• 제25권3호
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• pp.363-369
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• 2008

In the present work, the choice of the nano carbon black and optimum mixed ratio and effectiveness of the mixed carbon black to get a raw data for a manufacturing method of conductive complex board. Optimum mixed ratio of paper sludge & water was 1 : 2.5 for reformations. HB-41-Y was cheaper than Super-P with the single carbon black. Also electric conductivity of HB-41-Y($6.406{\times}10^{-2}\;{\Omega}cm^{-1}$) was about 6.5 times higher than Super-P($9.741{\times}10^{-3}\;{\Omega}cm^{-1}$) at 20 wt% carbon black. This time optimum mixture ratio of the paper sludge and the carbon black to be about 15 wt%, optimum mixed ratio HB-41Y and Graphite about 3:1 and its electric conductivity was $5.824{\times}10^{-2}\;{\Omega}cm^{-1}$.

• 한국전기전자재료학회논문지
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• 제14권10호
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• pp.861-867
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• 2001

In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks on NO$_{x}$ removal, we measure NO removal characteristics with and without sludge pellets in BaTiO$_3$-sludge packed-bed reactor of plate-plate geometry. NO initial concentration is 50 ppm balanced with air and a gas flow rate is 5ι/min. Gas temperature is changed from 25 to 10$0^{\circ}C$ to investigate the role of sludge pellet on removing active oxygen species and NO$_2$. BaTiO$_3$pellets is filled for coronal discharge at upstream of reactor and sludge pellets is filled for catalytic effect at downstream of reactor. The volume percent of sludge pellets to BaTiO$_3$pellets is changed from 0% to 100% and AC voltage is supplied to the reactor for discharging simulated gases. In the results, when sludge pellets is put at the downstream of plasma reactor, NO removal rate is slightly increased. However, NO$_2$and $O_3$ as by-products during NO removal is significantly decreased from 51ppm without sludge pellets to 5 ppm with sludge pellets and from 50 ppm without sludge pellets to 0.004ppm with sludge pellets, respectively. Therefore, NO$_{x}$(NO+NO$_2$) removal rate is increased up to 93%. It is thought that sludge pellet maybe react with active oxygen species and NO$_2$ generated by corona discharge in surface of BaTiO$_3$pellets, the then NO$_2$O$_3$as by-products are considerably decreased. When we increase gas temperature from room temperature to 10$0^{\circ}C$, NO removal rate is decreased, while NO$_2$ concentration is independent on gas temperature. These result suggest that the removal mechanism of active oxygen species and NO$_2$in sludge pellet is not absorption, but chemical reaction. Therefore we expect that sludge pellets exhausted for waterworks could be used as catalyst for NO$_{x}$ removal with high removal rate and low by-product.oduct.

• 콘크리트학회논문집
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• 제13권6호
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• pp.561-567
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• 2001

석산에서 부순잔골재를 생산시에는 다량의 슬러지 미립분이 배출되고 있다. 그러나, 실무현장에서는 슬러지의 일부를 매립용등에 제한적으로 사용할 뿐, 대부분은 방치되거나 무분별하게 버려지고 있어 막대한 경제적 손실과 환경오염 문제를 유발시키고 있다. 따라서 본 연구에서는 석산폐기물인 슬러지를 공장제품용 시멘트 모르타르 제조에 골재대체용 충전재로 활용하기 위하여, 골재 종류 및 모르타르 배합비 등에 미립분 혼입률을 변화시켜 시멘트 모르타르의 강도 및 흡수 특성을 검토하였다. 연구결과, 시멘트 모르타르 제품을 제조할 때 슬러지를 골재에 10% 정도 대체하여 혼입하게 되면 기존의 시멘트 모르타르 제품보다 향상된 품질의 제품이 생산될 수 있는 것이 확인되었다.

• 한국환경농학회지
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• 제14권1호
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• pp.72-81
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• 1995

하수슬러지의 국내 작물재배 실험결과와 슬러지 이용에 따르는 이해득실의 검토, 농경지 이용추세 등을 기초로 하여 다음과 같은 결론을 얻었다. (1) 하수슬러지는 수도와 옥수수재배에 있어서 수확량을 증대시키며 또한 곡립내의 중금속함량을 오히려 슬러지 주입이전보다 낮게 하는 효과를 나타냈다. 이러한 효과를 나타내는 주입농도는 20-40 ton (건조중량)/ha/yr로 나타났다. (2) 대부분의 중금속과 질소는 토양내에 잔존하며 침출되는 양은 매우 적게 나타나고 있다. (3) 우리 슬러지의 중금속함량은 미국의 상급슬러지보다 양호하므로 이의 이용을 위한 면밀한 검토를 통할 필요가 있다고 생각된다.

• Architectural research
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• 제12권1호
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• pp.49-55
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• 2010

Stone powder sludge is a by-product of the manufacturing process of crushed sand. Most of it is dumped with soil in landfills, and the disposal of stone powder sludge causes a major environmental problem. This paper investigates the applicability of stone powder sludge in fly ashbased geopolymer. For this, stone powder sludge was used to replace fly ash at a replacement ratio of 50% and 100% by weight. The compressive strength of the samples was measured and scanning electron microscopy/ energy dispersive spectroscopy (SEM/EDS) analysis and X-ray diffraction (XRD) were performed. The test results indicated that the optimum level of the alkali activator ratio ($Na_2SiO_3$/NaOH) for fly ash-based geopolymer using stone powder sludge was 1.5. The strength development is closely related to the NaOH solution concentration. In addition, the compressive strength of the sample cured at $25^{\circ}C$ was significantly improved between 7 days and 28 days, even though the strength of the sample showed the lowest value at 7 days. Microscopy results indicated that a higher proportion of unreacted fly ash spheres remained in the sample with 5M NaOH, and some pores on the surface of the sample were observed.

• 한국안전학회지
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• 제19권2호
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• pp.6-10
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• 2004

The magnetic polishing is the useful method to finish using magnetic power of magnet. This method is one of precision polishing techniques and has an aim of the clean technology using for the pure of gas and inside of the clean pipe for transportation. The magnetic abrasive polishing method is not so common for machine that it tis not spreaded widely. There are rarely researcher in this field because of non-effectiveness of magnetic abrasive. Therefore, in ths paper deals with development of the magnetic abrasive using sludge. In this development, abrasive grain WA and GC used to resin bond fabricated low temperature. And magnetic material was fabricated from the sludge which were crused into 200 mesh and average diameter ${\o}$1.2mm ball type. The XRD analysis result show that only WA and GC abrasive and sludge crystal peaks detected which explains resin bond was not any more chemical reaction. From SEM analysis it tis found that WA and GC abrasive and sludge were stron bonding with each other by bond.

• 산업경영시스템학회지
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• 제30권1호
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• pp.105-114
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• 2007

In this paper, we propose sludge collection strategies which allocate each sewage store of village to sewage treatment plants and decide the schedule of sludge collection in order to collect sludge efficiently. The strategies aim to decrease transportation cost with deciding proposed vehicle routing and scheduling the sludge collection. When we decide route of vehicles, we consider the collection time in sewage store of village, distance between sewage store of villages and vehicle information as average velocity of vehicle, operation time of vehicle driver. We also develop the SCMS (Sludge Collection Management System) based on windows system with real data which is used in certain circumstance. And we experiment to figure out vehicle route and transportation cost throughout changing input data.

• Korean Chemical Engineering Research
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• 제52권4호
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• pp.413-424
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• 2014

에너지원으로 바이오가스에 대한 잠재적 가능성이 인식되면서 최근에 바이오가스의 생산기술을 제고하고 에너지 효율을 개선하기 위한 기술개발이 지속적으로 진행되고 있다. 본 논문의 목적은 혐기성 소화 과정에서 바이오가스 생산을 증가시키기 위한 효과적이고 효율적인 슬러지 전처리 방법에 대하여 분석하였다. 이를 위해 본 논문에서는 각각의 전처리 방법의 장점과 단점을 분석하여 바이오가스 생산에 미치는 영향요인을 비교 분석하였다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제1권1호
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• pp.56-61
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• 2001

Activated sludge processes are broadly used in the biological wastewater treatment processes. The activated sludge processes are complex systems because of the many factors such as the variation of influent flowrate and ingredients, the complexity of biological reactions, and the various operation conditions. The main motivation o this research is to develop an intelligent control strategy for activated sludge process (ASP). ASP is a complex and nonlinear dynamic system owing to the characteristic of wastewater, the change in influent flowrate, weather conditions, and so on. The mathematical model of ASP also includes the uncertainty which is a ignored or unconsidered factor from process designers. The ASP model based on Matlabⓡ/Simulinkⓡ is developed in this paper. And the model performance is examined by IWA (International Water Association) and COST (European Cooperation in the filed of Scientific and Technical Research) data. The model tests derive steady-state results of 14 days. In this paper, fuzzy logic control approach is applied to handle DO concentrations. The fuzzy logic controller includes two inputs and one output to adjust air flowrate. The objective function for the optimization, in the implemented evolutionary strategy, is formed with focusing on improving the effluent quality and reducing the operating cost.